They will pull the main (company) fuse. In theory they aren't supposed to do this, and most fuses have a seal and label warning that it is not lawful to break the seal. In practice this is what everyone does, and it is accepted as perfectly OK (even by the electricity companies).
The electricity cable which comes into your house terminates in a box which has got a big fat fuse in it. From there it goes to your electricity meter then sometimes it goes to en electricity board isolating switch, but usually it goes straight to your consumer unit (the cables going into your consumer unit from the supply are called "tails".
To change the consumer unit, the electrician will remove the electrcity board's fuse.
Now, the fuse only cuts off the live side of the supply, but the neutral is connected to earth, so you should not get a shock off the neutral. The electrician will note what type of supply you have and do the necessary checks to ensure that he (or she) will not get a shock from the tails whilst the consumer unit is replaced.
HTH
Smudger
That's just dodging the question.
So what happens if you need a new fuse carrier on the incoming supply?
Hi,
If an electrican replaces your fuse-box with a consumer unit where is the mains electricity coming into your house switched off?
Sorry, I know this is a right Homer question but my understanding was always that you had a mains connection coming into your house which terminated in a fuse-box or, nowadays, a consumer-unit?
I am just trying to figure out how an electrician can safely 'switch off' the mains to do any work on the fuse-box/consumer unit? (Don't worry, I am not intending to try this myself but am simply curious.).
John.
That's the property of the leccy company, and their problem. I'd guess they send someone out from the 'qualified live working' team, suitably equipped!
There is a sealed fuse belonging to the electricity supplier before the meter. He will remove that to isolate the supply. It *should* only be done by the supplier, but from what I have seen in recent posts, it seems it's quite commonly done by independent sparks.
Ed
They'll work on it 'hot'. I've seen a film of those electric board chaps working on underground supply lines whilst still live.
Bloody long tongs (sp?) and bloody thick rubber gloves is all I could remember :-)
Hth Bill
It is only 230v, which is not particularly dangerous. A bloke from the electricity company comes in with a pair of 1000v gloves and does the work live. Whether he will bother to wear the gloves is another matter entirely.
Colin Bignell
Actually, from my experience, there are two blokes, one who does nothing and watches the other (in case there's a problem). You will notice that the soles of their shoes are very thick and insulating. Mine were installing a new meter. He cut away the live incoming feed neutral shroud and then the live inner, stuck a small piece of insulating tape over the live end, fed it through the wall with one hand while feeling for the end of it with the other hand (no gloves!) then wired it up (all live). The wire cutters were quite fancy mind with huge plastic shrouds to stop your hands slipping down onto the exposed metal.
It's true that 230V isn't particularly high but there are quite severe burn risks if you short live to neutral with something metal - the next fuse up the line is likely to be 1000A or something.
A brother of someone I know worked as a gas fitter. One day he was removing an old steel gas pipe by cutting through it with a hacksaw whwn he "discovered" the leccy people (a long time ago) had laid the house main up the middle of it (because it was there I guess). He received flash burns from vaporised hacksaw blade etc. and was deeply shocked (as in ordinary shock not electric). Two weeks later all his teeth fell out (presumed to be the shock). Bummer.
In my last house, we had a problem with the feed from the substation. This "problem" caused regular severe brownouts and occasional blackouts. The leccy board took two years to fingure out the problem, which turned out to be a joint under the pavement which was letting water in. The joint was apparently undocumented and they only found it because the tarmac above the joint eventually ruptured. I spoke to the leccy board spark on the day they fixed it and he told me that every time there was a blackout, he or one of his mates just came down and replaced the fuse, which was 300Amp. This fuse supplied about 20 houses. Now that's what I call diversity!
Smudger
"nightjar .uk.com>"
Why dont they have a neutral link in which can be removed? I seem to think there are two fuse holders under our meter although I cant remember for sure.
Quite agree, the saying "It's volts that jolts, mils that kills" is very true.
Unfortunately the mains has more than enough volts to make considerable currents flow. Even if you don't contact the live directly a short to almost anything will cause a minor explosion, getting sprayed by molten metal is not a good idea. Never underestimate the power available from the mains.
Even 110v. The current (amps) kills and 110v can deliver the same as 230v.
Or in our world, where the standard laws of physics apply, just under half as much - not the same acurrent for a given resistance.
Amazing from a man who operates drills under water. The points is that 110v can deliver enough current to kill/Many people think 110v is "safe". People have died when they have received belts from 12v batteries because it delivered enough current.
Yes, it can. But that isn't what ou said.
Bullshit.
Thanks all for the info - fascinating stuff and something that I am more than happy to stay well clear of. Some of the replies remind me of a BBC programme I saw a few years ago about electricity which showed some guy from the National Grid, in what can only be described as a silver wire mesh spacesuit and gloves, reaching out and touching a million volts?/amps?/big powerful lump of electricity :-)... apparently the suit worked like a Faraday Cage and insulated him completely... braver man than I though I do admit...
John.
In message , John Smith writes
as long he kept believing it was working he was safe ;-)
"a" wrote >
| Why dont they have a neutral link in which can be removed?
There often is a neutral link which can be removed, but the neutral is also the earth in PME supplies, and the earth MUST NOT be broken.
| I seem to think there are two fuse holders under our meter | although I cant remember for sure.
The neutral should not be fused; if you have double-pole fuses you need rewiring.
Owain
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